Question

MEDAL
This pedigree chart tracks the inheritance of a recessive trait that is not sex-linked. Based on the information in the chart, which of the following statements is true?

Answer 1

Individual #11 must be homozygous for the recessive trait.
Individuals #3 and #4 must be heterozygous for the trait.
Individual #2 must be heterozygous dominant for the trait.
Individual #9 must be homozygous dominant for the trait.

Answer 2

this are the option but i know is not A or B

Answer 3

i think is C

Answer 4

your right it would be C

Answer 5

You sure?

Answer 6

yea

Answer 7

can you show me how you did it tho

Answer 8

C is the correct answer. This is because #1 is homozygous recessive and #2 is heterozygous or homozygous dominant, hence at least hinting that #8 could be heterozygous. What confirms is the children of #8. For any children of #8 and 9 to be homozygous recessive and be affected by the disease, both should carry at least one recessive allele. Hence, #8 has a recessive allele and the fact that it is not affected proves that it is because of the dominant allele in it. Hence, heterozygous.